1. Field of the Invention
The device of this invention resides in the area of valve adjustment means for internal combustion engines having overhead cams or rocker arms and more particularly relates to a valve spring retainer including hydraulic means for adjustment of the gap between the cam shaft and/or rocker arm and valve stem.
2. History of the Prior Art
In typical overhead cam engines the valves are operated by a rocker arm pushing on the valve stem or cam shaft pushing on bucket tappets. The rocker arm is usually actuated by a cam located in association therewith. In order to provide for the thermal expansion of the valve stem due to the heat created by the fuel combustion within the engine, gaps are usually provided between the valve stem and rocker arm. Adjustment means are provided to change this gap. Although such changes are made relatively simple by hydraulic valve lifters, in many instances there is a penalty paid in increased weight as well as decreased efficiency and reliability of the hydraulic lifter.